Protocol for a remotely controlled videoconferencing robot

ABSTRACT

A robotic system that includes a robot and a remote station. The remote station can generate control commands that are transmitted to the robot through a broadband network. The control commands can be interpreted by the robot to induce action such as robot movement or focusing a robot camera. The robot can generate reporting commands that are transmitted to the remote station through the broadband network. The reporting commands can provide positional feedback or system reports on the robot.

BACKGROUND OF THE INVENTION 1. Field of the Invention

The subject matter disclosed generally relates to the field of robotics.

2. Background Information

There is a growing need to provide remote health care to patients that have a variety of ailments ranging from Alzheimers to stress disorders. To minimize costs it is desirable to provide home care for such patients. Home care typically requires a periodic visit by a health care provider such as a nurse or some type of assistant. Due to financial and/or staffing issues the health care provider may not be there when the patient needs some type of assistance. Additionally, existing staff must be continuously trained, which can create a burden on training personnel. It would be desirable to provide a system that would allow a health care provider to remotely care for a patient without being physically present.

Robots have been used in a variety of applications ranging from remote control of hazardous material to assisting in the performance of surgery. For example, U.S. Pat. No. 5,762,458 issued to Wang et al. discloses a system that allows a surgeon to perform minimally invasive medical procedures through the use of robotically controlled instruments. One of the robotic arms in the Wang system moves an endoscope which has a camera that allows a surgeon to view a surgical area of a patient.

Tele-robots such as hazardous waste handlers and bomb detectors may contain a camera that allows the operator to view the remote site. Canadian Pat. No. 2289697 issued to Treviranus, et al. discloses a teleconferencing platform that has both a camera and a monitor. The Treviranus patent also discloses embodiments with a mobile platform, and different mechanisms for moving the camera and the monitor.

Publication Application No. US-2003-0050233-A1 discloses a remote robotic system wherein a plurality of remote stations can control a plurality of robotic arms used to perform a minimally invasive medical procedure. Each remote station can receive a video image provided by the endoscope inserted into the patient. The remote stations are linked to the robotic system by a dedicated communication link. The dedicated link is required to insure communication quality during the performance of a remote surgical procedure. Dedicated links are not practical for a robotic product that can be used by a number of operators.

BRIEF SUMMARY OF THE INVENTION

A robotic system that includes a robot and a remote station that communicate through a broadband network. Control commands can be sent from the remote station to the robot through the broadband network. Reporting commands can be sent to the remote station from the robot.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an illustration of a robotic system;

FIG. 2 is a schematic of an electrical system of a robot;

FIG. 3 is a further schematic of the electrical system of the robot;

FIG. 4 is side view of the robot;

FIG. 5 is a top perspective view of a holonomic platform of the robot;

FIG. 6 is a side perspective view of a roller assembly of the holonomic platform;

FIG. 7 is a bottom perspective view showing a pedestal assembly of the robot;

FIG. 8 is a sectional view showing an actuator of the pedestal assembly;

FIG. 9 is a side view of a robot head.

DETAILED DESCRIPTION

Disclosed is a robotic system that includes a robot and a remote station. The remote station can generate control commands that are transmitted to the robot through a broadband network. The control commands can be interpreted by the robot to induce action such as robot movement or focusing a robot camera. The robot can generate reporting commands that are transmitted to the remote station through the broadband network. The reporting commands can provide positional feedback or system reports on the robot.

Referring to the drawings more particularly by reference numbers, FIG. 1 shows a robotic system 10. The robotic system 10 includes a robot 12, a base station 14 and a remote control station 16. The remote control station 16 may be coupled to the base station 14 through a network 18. By way of example, the network 18 may be either a packet switched network such as the Internet, or a circuit switched network such has a Public Switched Telephone Network (PSTN), or other broadband system. The base station 14 may be coupled to the network 18 by a modem 20 or other broadband network interface device.

The remote control station 16 may include a computer 22 that has a monitor 24, a camera 26, a microphone 28 and a speaker 30. The computer 22 may also contain an input device 32 such as a joystick or a mouse. The control station 16 is typically located in a place that is remote from the robot 12. Although only one robot 12 and one station 16 are shown, it is to be understood that the system 10 may have a plurality of robots 12 and/or a plurality of remote stations that communicate through the broadband network. In general any number of robots 12 may be controlled by any number of remote stations. For example, one remote station 16 may be coupled to a plurality of robots 12, or one robot 12 may be coupled to a plurality of remote stations 16.

The robot 12 includes a movement platform 34 that is attached to a robot housing 36. Also attached to the robot housing 36 are a camera 38, a monitor 40, a microphone(s) 42 and a speaker 44. The microphone 42 and speaker 30 may create a stereophonic sound. The robot 12 may also have an antenna 45 that is wirelessly coupled to an antenna 46 of the base station 14. The system 10 allows a user at the remote control station 16 to move the robot 12 through the input device 32. The robot camera 38 is coupled to the remote monitor 24 so that a user at the remote station 16 can view a patient. Likewise, the robot monitor 40 is coupled to the remote camera 26 so that the patient can view the user. The microphones 28 and 42, and speakers 30 and 44, allow for audible communication between the patient and the user.

Each remote station computer 22 may operate Microsoft OS software and WINDOWS XP or other operating systems such as LINUX. The remote computer 22 may also operate a video driver, a camera driver, an audio driver and a joystick driver. The video images may be transmitted and received with compression software such as MPEG CODEC.

FIGS. 2 and 3 show an embodiment of the robot 12. The robot 12 may include a high level control system 50 and a low level control system 52. The high level control system 50 may include a processor 54 that is connected to a bus 56. The bus is coupled to the camera 38 by an input/output (I/O) port 58, and to the monitor 40 by a serial output port 60 and a VGA driver 62. The monitor 40 may include a touchscreen function that allows the patient to enter input by touching the monitor screen.

The speaker 44 is coupled to the bus 56 by a digital to analog converter 64. The microphone 42 is coupled to the bus 56 by an analog to digital converter 66. The high level controller 50 may also contain random access memory (RAM) device 68, a non-volatile RAM device 70 and a mass storage device 72 that are all coupled to the bus 62. The mass storage device 72 may contain medical files of the patient that can be accessed by the user at the remote control station 16. For example, the mass storage device 72 may contain a picture of the patient. The user, particularly a health care provider, can recall the old picture and make a side by side comparison on the monitor 24 with a present video image of the patient provided by the camera 38. The robot antennae 45 may be coupled to a wireless transceiver 74. By way of example, the transceiver 74 may transmit and receive information in accordance with IEEE 802.11b.

The controller 54 may operate with a LINUX OS operating system. The controller 54 may also operate MS WINDOWS along with video, camera and audio drivers for communication with the remote control station 16. Video information may be transceived using MPEG CODEC compression techniques. The software may allow the user to send e-mail to the patient and vice versa, or allow the patient to access the Internet. In general the high level controller 50 operates to control the communication between the robot 12 and the remote control station 16.

The high level controller 50 may be linked to the low level controller 52 by serial ports 76 and 78. The low level controller 52 includes a processor 80 that is coupled to a RAM device 82 and non-volatile RAM device 84 by a bus 86. The robot 12 contains a plurality of motors 88 and motor encoders 90. The encoders 90 provide feedback information regarding the output of the motors 88. The motors 88 can be coupled to the bus 86 by a digital to analog converter 92 and a driver amplifier 94. The encoders 90 can be coupled to the bus 86 by a decoder 96. The robot 12 also has a number of proximity sensors 98 (see also FIG. 1). The position sensors 98 can be coupled to the bus 86 by a signal conditioning circuit 100 and an analog to digital converter 102.

The low level controller 52 runs software routines that mechanically actuate the robot 12. For example, the low level controller 52 provides instructions to actuate the movement platform to move the robot 12. The low level controller 52 may receive movement instructions from the high level controller 50. The movement instructions may be received as movement commands from the remote control station 16. Although two controllers are shown, it is to be understood that the robot 12 may have one controller controlling the high and low level functions.

The various electrical devices of the robot 12 may be powered by a battery(ies) 104. The battery 104 may be recharged by a battery recharger station 106 (see also FIG. 1). The low level controller 52 may include a battery control circuit 108 that senses the power level of the battery 104. The low level controller 52 can sense when the power falls below a threshold and then send a message to the high level controller 50. The high level controller 50 may include a power management software routine that causes the robot 12 to move so that the battery 104 is coupled to the recharger 106 when the battery power falls below a threshold value. Alternatively, the user can direct the robot 12 to the battery recharger 106. Additionally, the battery 104 may be replaced or the robot 12 may be coupled to a wall power outlet by an electrical cord (not shown).

FIG. 4 shows an embodiment of the robot 12. The robot 12 may include a holonomic platform 110 that is attached to a robot housing 112. The holonomic platform 110 provides three degrees of freedom to allow the robot 12 to move in any direction.

The robot 12 may have an pedestal assembly 114 that supports the camera 38 and the monitor 40. The pedestal assembly 114 may have two degrees of freedom so that the camera 26 and monitor 24 can be swiveled and pivoted as indicated by the arrows.

As shown in FIG. 5 the holonomic platform 110 may include three roller assemblies 120 that are mounted to a base plate 121. The roller assemblies 120 are typically equally spaced about the platform 110 and allow for movement in any direction, although it is to be understood that the assemblies may not be equally spaced.

The robot housing 112 may include a bumper 122. The bumper 122 may be coupled to optical position sensors 123 that detect when the bumper 122 has engaged an object. After engagement with the object the robot can determine the direction of contact and prevent further movement into the object.

FIG. 6 shows an embodiment of a roller assembly 120. Each assembly 120 may include a drive ball 124 that is driven by a pair of transmission rollers 126. The assembly 120 may include a retainer ring 128 and a plurality of bushings 130 that captures and allows the ball 124 to rotate in an x and y direction but prevents movement in a z direction. The assembly also holds the ball under the transmission rollers 126.

The transmission rollers 126 are coupled to a motor assembly 132. The assembly 132 corresponds to the motor 88 shown in FIG. 3. The motor assembly 132 includes an output pulley 134 attached to a motor 136. The output pulley 134 is coupled to a pair of ball pulleys 138 by a drive belt 140. The ball pulleys 138 are each attached to a transmission bracket 142. The transmission rollers 126 are attached to the transmission brackets 142.

Rotation of the output pulley 134 rotates the ball pulleys 138. Rotation of the ball pulleys 138 causes the transmission rollers 126 to rotate and spin the ball 124 through frictional forces. Spinning the ball 124 will move the robot 12. The transmission rollers 126 are constructed to always be in contact with the drive ball 124. The brackets 142 allow the transmission rollers 126 to freely spin in a direction orthogonal to the drive direction when one of the other roller assemblies 120 is driving and moving the robot 12.

As shown in FIG. 7, the pedestal assembly 114 may include a motor 150 that is coupled to a gear 152 by a belt 154. The gear 152 is attached to a shaft 156. The shaft 156 is attached to an arm 158 that is coupled to the camera 38 and monitor 40 by a bracket 160. Activation of the motor 150 rotates the gear 152 and sleeve 156, and causes the camera 38 and monitor 40 to swivel (see also FIG. 4) as indicated by the arrows 4.

As shown in FIG. 8, the assembly 114 may further include a tilt motor 162 within the arm 158 that can cause the monitor 40 and camera 38 to pivot as indicated by the arrows 5. The tilt motor 162 may rotate a worm 164 that rotates a worm gear 166. The pin 168 is rigidly attached to both the worm gear 166 and the bracket 160 so that rotation of the gear 166 pivots the camera 38 and the monitor 40. The camera 38 may also include a zoom feature to provide yet another degree of freedom for the operator.

In operation, the robot 12 may be placed in a home or a facility where one or more patients are to be monitored and/or assisted. The facility may be a hospital or a residential care facility. By way of example, the robot 12 may be placed in a home where a health care provider may monitor and/or assist the patient. Likewise, a friend or family member may communicate with the patient. The cameras and monitors at both the robot and remote control stations allow for teleconferencing between the patient and the person at the remote station(s).

The robot 12 can be maneuvered through the home or facility by manipulating the input device 32 at a remote station 16. The robot 10 may be controlled by a number of different users. To accommodate for this the robot may have an arbitration system. The arbitration system may be integrated into the operating system of the robot 12. For example, the arbitration technique may be embedded into the operating system of the high-level controller 50.

By way of example, the users may be divided into classes that include the robot itself, a local user, a caregiver, a doctor, a family member, or a service provider. The robot 12 may override input commands that conflict with robot operation. For example, if the robot runs into a wall, the system may ignore all additional commands to continue in the direction of the wall. A local user is a person who is physically present with the robot. The robot could have an input device that allows local operation. For example, the robot may incorporate a voice recognition system that receives and interprets audible commands.

A caregiver is someone who remotely monitors the patient. A doctor is a medical professional who can remotely control the robot and also access medical files contained in the robot memory. The family and service users remotely access the robot. The service user may service the system such as by upgrading software, or setting operational parameters.

The robot 12 may operate in one of two different modes; an exclusive mode, or a sharing mode. In the exclusive mode only one user has access control of the robot. The exclusive mode may have a priority assigned to each type of user. By way of example, the priority may be in order of local, doctor, caregiver, family and then service user. In the sharing mode two or more users may share access with the robot. For example, a caregiver may have access to the robot, the caregiver may then enter the sharing mode to allow a doctor to also access the robot. Both the caregiver and the doctor can conduct a simultaneous tele-conference with the patient.

The arbitration scheme may have one of four mechanisms; notification, timeouts, queue and call back. The notification mechanism may inform either a present user or a requesting user that another user has, or wants, access to the robot. The timeout mechanism gives certain types of users a prescribed amount of time to finish access to the robot. The queue mechanism is an orderly waiting list for access to the robot. The call back mechanism informs a user that the robot can be accessed. By way of example, a family user may receive an e-mail message that the robot is free for usage. Tables I and II, show how the mechanisms resolve access request from the various users.

TABLE I Access Medical Command Software/Debug Set User Control Record Override Access Priority Robot No No Yes (1) No No Local No No Yes (2) No No Caregiver Yes Yes Yes (3) No No Doctor No Yes No No No Family No No No No No Service Yes No Yes Yes Yes

TABLE II Requesting User Local Caregiver Doctor Family Service Current Local Not Allowed Warn current user of Warn current user of Warn current user of Warn current user of User pending user pending user pending user pending user Notify requesting user Notify requesting user Notify requesting user Notify requesting user that system is in use that system is in use that system is in use that system is in use Set timeout Set timeout = 5 m Set timeout = 5 m No timeout Call back Call back Caregiver Warn current user of Not Allowed Warn current user of Warn current user of Warn current user of pending user. pending user pending user pending user Notify requesting user Notify requesting user Notify requesting user Notify requesting user that system is in use. that system is in use that system is in use that system is in use Release control Set timeout = 5 m Set timeout = 5 m No timeout Queue or callback Callback Doctor Warn current user of Warn current user of Warn current user of Notify requesting user Warn current user of pending user pending user pending user that system is in use pending user Notify requesting user Notify requesting user Notify requesting user No timeout Notify requesting user that system is in use that system is in use that system is in use Queue or callback that system is in use Release control Set timeout = 5 m No timeout No timeout Callback Callback Family Warn current user of Notify requesting user Warn current user of Warn current user of Warn current user of pending user that system is in use pending user pending user pending user Notify requesting user No timeout Notify requesting user Notify requesting user Notify requesting user that system is in use Put in queue or that system is in use that system is in use that system is in use Release Control callback Set timeout = 1 m Set timeout = 5 m No timeout Queue or callback Callback Service Warn current user of Notify requesting user Warn current user of Warn current user of Not Allowed pending user that system is in use request pending user Notify requesting user No timeout Notify requesting user Notify requesting user that system is in use Callback that system is in use that system is in use No timeout No timeout No timeout Callback Queue or callback

The information transmitted between the station 16 and the robot 12 may be encrypted. Additionally, the user may have to enter a password to enter the system 10. A selected robot is then given an electronic key by the station 16. The robot 12 validates the key and returns another key to the station 16. The keys are used to encrypt information transmitted in the session.

The robot 12 and remote station 16 transmit commands through the broadband network 18. The commands can be generated by the user in a variety of ways. For example, commands to move the robot may be generated by moving the joystick 32 (see FIG. 1). The commands are preferably assembled into packets in accordance with TCP/IP protocol. Table III provides a list of control commands that are generated at the remote station and transmitted to the robot through the network.

TABLE III Control Commands Command Example Description drive drive 10.0 0.0 5.0 The drive command directs the robot to move at the specified velocity (in cm/sec) in the (x, y) plane, and turn its facing at the specified rate (degrees/sec). goodbye goodbye The goodbye command terminates a user session and relinquishes control of the robot gotoHomePosition gotoHomePosition 1 The gotoHomePosition command moves the head to a fixed “home” position (pan and tilt), and restores zoom to default value. The index value can be 0, 1, or 2. The exact pan/tilt values for each index are specified in robot configuration files. head head vel pan 5.0 tilt The head command controls the head motion. 10.0 It can send commands in two modes, identified by keyword: either positional (“pos”) or velocity (“vol”). In velocity mode, the pan and tilt values are desired velocities of the head on the pan and tilt axes, in degree/sec. A single command can include just the pan section, or just the tilt section, or both. keepalive keepalive The keepalive command causes no action, but keeps the communication (socket) link open so that a session can continue. In scripts, it can be used to introduce delay time into the action. odometry odometry 5 The odometry command enables the flow of odometry messages from the robot. The argument is the number of times odometry is to be reported each second. A value of 0 turns odometry off. reboot reboot The reboot command causes the robot computer to reboot immediately. The ongoing session is immediately broken off. restoreHeadPosition restoreHeadPosition The restoreHeadPosition functions like the gotoHomePosition command, but it homes the head to a position previously saved with gotoHomePosition. saveHeadPosition saveHeadPosition The saveHeadPosition command causes the robot to save the current head position (pan and tilt) in a scratch location in temporary storage so that this position can be restored. Subsequent calls to “restoreHeadPosition” will restore this saved position. Each call to saveHeadPosition overwrites any previously saved position. setCameraFocus setCameraFocus 100.0 The setCameraFocus command controls focus for the camera on the robot side. The value sent is passed “raw” to the video application running on the robot, which interprets it according to its own specification. setCameraZoom setCameraZoom 100.0 The setCameraZoom command controls zoom for the camera on the robot side. The value sent is passed “raw” to the video application running on the robot, which interprets it according to its own specification. shutdown Shutdown The shutdown command shuts down the robot and powers down its computer. stop stop The stop command directs the robot to stop moving immediately. It is assumed this will be as sudden a stop as the mechanism can safely accommodate. timing Timing 3245629 500 The timing message is used to estimate message latency. It holds the UCT value (seconds + milliseconds) of the time the message was sent, as recorded on the sending machine. To do a valid test, you must compare results in each direction (i.e., sending from machine A to machine B, then from machine B to machine A) in order to account for differences in the clocks between the two machines. The robot records data internally to estimate average and maximum latency over the course of a session, which it prints to log files. userTask userTask “Jane Doe” The userTask command notifies the robot of “Remote Visit” the current user and task. It typically is sent once at the start of the session, although it can be sent during a session if the user and/or task change. The robot uses this information for record-keeping.

Table IV provides a list of reporting commands that are generated by the robot and transmitted to the remote station through the network.

TABLE IV Reporting Commands Command Example Description abnormalExit abnormalExit This message informs the user that the robot software has crashed or otherwise exited abnormally. Te robot software catches top- level exceptions and generates this message if any such exceptions occur. bodyType bodyType 3 The bodyType message informs the station which type body (using the numbering of the mechanical team) the current robot has. This allows the robot to be drawn correctly in the station user interface, and allows for any other necessary body-specific adjustments. driveEnabled driveEnabled true This message is sent at the start of a session to indicate whether the drive system is operational. emergencyShutdown emergencyShutdown This message informs the station that the robot software has detected a possible “runaway” condition (an failure causing the robot to move out of control) and is shutting the entire system down to prevent hazardous motion. odometry odometry 10 20 340 The odometry command reports the current (x, y) position (cm) and body orientation (degrees) of the robot, in the original coordinate space of the robot at the start of the session. sensorGroup group_data Sensors on the robot are arranged into groups, each group of a single type (bumps, range sensors, charge meter, etc.) The sensorGroup message is sent once per group at the start of each session. It contains the number, type, locations, and any other relevant data for the sensors in that group. The station assumes nothing about the equipment carried on the robot; everything it knows about the sensors comes from the sensorGroup messages. sensorState groupName state data The sensorState command reports the current state values for a specified group of sensor. The syntax and interpretation for the state data is specific to each group. This message is sent once for each group at each sensor evaluation (normally several times per second). systemError systemError This message informs the station user of a driveController failure in one of the robot's subsystems. The error_type argument indicates which subsystem failed, including driveController, sensorController, headHome. systemInfo systemInfo wireless 45 This message allows regular reporting of information that falls outside the sensor system such as wireless signal strength. text text “This is some The text string sends a text string from the text” robot to the station, where the string is displayed to the user. This message is used mainly for debugging. version version 1.6 This message identifies the software version currently running on the robot. It is sent once at the start of the session to allow the station to do any necessary backward compatibility adjustments.

FIG. 9 shows a robot head 200 that can both pivot and spin the camera 38 and the monitor 40. The robot head 200 can be similar to the robot 12 but without the platform 110. The robot head 200 may have the same mechanisms and parts to both pivot the camera 38 and monitor 40 about the pivot axis 4, and spin the camera 38 and monitor 40 about the spin axis 5. The pivot axis may intersect the spin axis. Having a robot head 200 that both pivots and spins provides a wide viewing area. The robot head 200 may be in the system either with or instead of the mobile robot 12.

While certain exemplary embodiments have been described and shown in the accompanying drawings, it is to be understood that such embodiments are merely illustrative of and not restrictive on the broad invention, and that this invention not be limited to the specific constructions and arrangements shown and described, since various other modifications may occur to those ordinarily skilled in the art. 

What is claimed is:
 1. A robot system that communicates through a broadband network, comprising: a plurality of robots, each having a camera and a monitor; and, a plurality of remote stations, each having a camera and a monitor, each of the plurality of remote stations can establish a communication session with each of the plurality of robots, and at least one of the plurality of remote stations generates a goodbye command that terminates a communication session with one of the plurality of robots and relinquishes control of the robot such that another of the plurality of the remote stations can establish a communication session with the robot. 